1. Field of the Invention
The present invention relates to a heat dissipation device and particularly to a heat dissipation device for removing heat from LED chips.
2. Description of Related Art
An LED lamp is a type of solid state lighting that utilizes light-emitting diodes (LEDs) as a source of illumination. An LED is a device for transferring electricity to light by using a theory that, if a current is made to flow in a forward direction in a junction comprising two different semiconductors, electrons and holes are coupled at the junction region to generate a light beam. The LED has an advantage in that it is resistant to shock, and has an almost eternal lifetime under a specific condition; thus, the LED lamp is intended to be a cost-effective yet high quality replacement for incandescent and fluorescent lamps.
A high-powered LED light device produces considerable amount of heat, which may cause performance degrade or even damage of the device if the heat is not removed from LED chips of the device efficiently. In an LED light device, the LED chips which are mounted on a substrate are the core for generating light and heat. A transparent cover may be used to cover the LED chips for protecting the LED chips from foreign articles. Although there are many different designs, the major heat dissipation route for the heat produced by the LED chips is usually managed through the substrate to which the LED chips are mounted and a metal heat sink thermally connecting with the substrate.
When the LED light device is used as an outdoor LED lamp, it usually requires a waterproof sealing for the LED chips to protect the LED chips from rain. The LED lamp comprises a heat sink for dissipating heat generated by the LED chips. In a sunny day, the heat sink is exposed directly to the sunlight and heated by sunlight. The heat absorbed by the heat sink from the sunlight is transferred to the LED chips which are in contact with the heat sink. Therefore, the temperature of the LED chips raises enormously, which affects the life-span of the LED chips.
What is needed, therefore, is a heat dissipation device for an LED light device which has an improved structure and overcomes the abovementioned disadvantage.